Every one is tech because of the near-future setting in the "real world". They are staying away from fantasy and magic, that belongs to Warcraft. Although, an argument can be made that Winston is super-science. And there's definitely something mystical about Zenyatta and Hanzo. I love the idea of Zenyatta, a Zen monk android.

Like I said, I made some Zodiac Overwatch. But, I didn't follow the official uniform colors. As I used blue, white and gold a lot. Like a whole lot.

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Still, it looks that the heroic characters in Overwatch are all uniquely designed anyway. With maybe the uniform guys as only common troopers, e.g. grunts.

The character designs to vary widely, like any good superhero team should.